In classes and seminars, I am involved with around the country a frequent question that is asked is should we replace backflow prevention assemblies, or should we repair them when they fail our testing. As with so many issues today this one has many variables to it. How old is the assembly? Are the repair parts readily available? Is it less expensive for your customer to replace rather that repair? How difficult will the repair be? Is it simply time to update the assembly? The list goes on and on. The correct answer to this question is “it depends”. There are several simple questions we need to ask related to this question.

How many assemblies fail their annual test?

Over the last 42 years I have tested, repaired or replaced thousands of backflow assemblies. I have also taught several thousand people to test and repair backflow assemblies. In speaking with people in many areas of the nation I would put the number of assemblies fail annual testing between 20 and 25 percent. Water conditions are an important factor. Many failures are caused dirt and debris, others can be as a result of severe water hammer, backpressure or a number of other factors. At times repairing an assembly without researching the cause of the failure make a temporary fix of a larger problem.

How often is the issue dirt and debris?

That really depends on a number of factors. A large water main break may stir up dirt and debris in a system and cause abnormal flow velocity. Older systems may also create issues.

How old is the assembly?

Many people may disagree with me on this, but it is a critical factor to consider. The fact that parts may be available must not be the only reason to attempt a repair.

Are Repair Parts Available Locally?

This is an important consideration. As someone who worked as a service plumber for many years, at times it made perfect sense to replace smaller assemblies if our service people did not have the parts available on the truck but did have a replacement assembly available on hand. Most plumbing supply houses do not stock even rubber parts kits for most assemblies and although many parts suppliers can provide parts overnight the additional cost and time must be considered. The cost of labor for ordering parts to return and repair the assembly was greater than simply replacing the assembly in many situations. How much a company charges for its services may be a factor in this decision. It is based on the overhead a company has, including wages, benefits, taxes, insurance, and a host of other costs. It is also influenced by profit margins, location, market share, experience, and many other factors. I have attended conferences where individuals working in the water industry spoke out on the topic of what a tester or repairer should charge. It should not be a concern to water suppliers, inspectors, or others working in the same field. It is between the consumer and the testing or repair company. I understand the focus on working to ensure that the testing and repair is completed correctly by people certified or licensed to do that work. The cost of the job or the decision to replace an assembly belongs to the consumer and the professional they contract with. If the consumer is required to assume the cost of installation, testing, and maintenance of a backflow prevention assembly then they have the right to decide who does that work as long as that provider meets the local requirements.  Unless a water supplier is prepared to assume those costs and responsibility, they have no right dictate those decisions.

What material is the Assembly Body?

Is it a galvanized assembly? If the valve is epoxy coated what is the condition of the coating? Are the internal parts leaded brass that do not comply with the current safe drinking water act lead levels? All these things need to be considered and evaluated. The breakdown of a valve body’s coating or a mineral or corrosion build up within an assembly can affect a valve’s function and life span.

Many years ago, as a new, inexperienced tester, I flooded a department store when a six-inch Hersey 6CM reduced pressure principle assembly’s relief valve went into total discharge as I was flushing the number two test cock. The internal waterway in the valve’s galvanized body which supplies high pressure water to the relief valves diaphragm had become completely blocked. It had blocked with pressure on the diaphragm. Because of the location of the number two test cock, which was downstream of the blockage in the internal waterway, when I opened the test cock and relieved the pressure on the diaphragm the assembly relief valve opened 100%. There was no drainage in the room and the number one shutoff was frozen in the open position. By the time I was able to get the water service off more that 20,000 gallons of water had flown into the store’s main floor area. Later in my career, whenever it was possible, I replaced every galvanized assembly I came across.

What is the Cost and Difficulty of the Repair?

Labor is a large cost when professional companies test and repair backflow prevention assemblies. Many larger, older assemblies can be difficult to repair, and parts may be very expensive and difficult or impossible to find. Each situation should be looked at carefully and a cost comparison made which includes future repairs.

Is the Assembly in a Confined Space?

Are your people confined space trained and certified? The cost of repairs of assemblies in confined space needs to be considered. Bringing the valve out of a vault or pit into an approved enclosure may be the most cost-effective solution for the consumer in the long run.

The answers to these seven questions should give you the information needed to make the correct decision. Just because parts are available does not mean the best call for your customer is to attempt a repair. It is a judgement call each off us must make. Like so many things in the cross-connection control industry it is a unique situation almost every time. We don’t have one-size fits all solutions in our industry. This is true for the selection of the proper protection and it is something that from start to finish compels us to look carefully at every decision we make and every action we take. The industry has come a long way. Assemblies look very different than they did in the past. They are smaller; easier to repair and maintain and have less pressure loss and higher flow rates. The one thing we will never stop is change.

About the Author

Sean is a 40 year member of the United Association Local 524 Scranton Pa. He has worked in all phases of the plumbing and mechanical industry and is a licensed master plumber. Sean is a Past President of the American Society of Sanitary Engineering. Sean is also the member of the ASSE Cross-Connection Control, Technical Committee. Sean is employed by IAPMO as the Vice President of Operations for the IAPMO Backflow Prevention Institute.